Butenylspinosyns a natural example of genetic en

Authors: Donald R Hahn Gary Gustafson Clive Waldron Brian Bullard James D Jackson Jon Mitchell

Publish Date: 2005/09/23

Volume: 33, Issue: 2, Pages: 94-104

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Abstract

Spinosyns a novel class of insect active macrolides produced by Saccharopolyspora spinosa are used for insect control in a number of commercial crops Recently a new class of spinosyns was discovered from S pogona NRRL 30141 The butenylspinosyns also called pogonins are very similar to spinosyns differing in the length of the side chain at C21 and in the variety of novel minor factors The butenylspinosyn biosynthetic genes bus were cloned on four cosmids covering a contiguous 110kb region of the NRRL 30141 chromosome Their function in butenylspinosyn biosynthesis was confirmed by a lossoffunction deletion and subsequent complementation by cloned genes The coding sequences of the butenylspinosyn biosynthetic genes and the spinosyn biosynthetic genes from S spinosa were highly conserved In particular the PKScoding genes from S spinosa and S pogona have 91–94 nucleic acid identity with one notable exception The butenylspinosyn gene sequence codes for one additional PKS module which is responsible for the additional two carbons in the C21 tail The DNA sequence of spinosyn genes in this region suggested that the S spinosa spnA gene could have been the result of an inframe deletion of the S pogona busA gene Therefore the butenylspinosyn genes represent the putative parental gene structure that was naturally engineered by deletion to create the spinosyn genes

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